A prominent feature of nervous systems is their ability to change in response to signals from the environment. This feature is even true within the brain, where the local cellular environment can determine the development and organization of several areas. It has been known for some years that activity in the visual pathways during development of many animals can affect the organization and response properties of cells in the visual system in the adult. Little is known about the mechanisms through which visual activity might modulate the properties of individual nerve cells, or neurons, in central areas. This project uses the simple model system of the optic tectum, a part of the midbrain in frogs, to see how interruption of activity in the visual pathway affects the presence and action in the tectum of two neurotransmitter chemical compounds. Electrophysiological, immunohistochemical and microscopic imaging techniques are used to assay the physiological response and neurotransmitter expression in the optic tectum, and to see whether changes are mediated by specific components of the activity of the cells that form the optic nerve from the eye to the brain. Results from this work will enhance our understanding of how environmental input shapes the properties of brain areas that receive this information. It will have an impact beyond visual neuroscience to developmental neuroscience, developmental biology, and research in fields that deal with information encoding and storage, and learning and memory.
